Synthesis
Using methyl acetoacetate as the starting material, the reaction was carried out according to the conditions listed in Table 1. During the reaction, the operation was kept consistent with Example 1 except for adjusting the catalyst type, methanol dosage, reaction temperature, reaction time, the molar ratio of the metal in the catalyst and the molar ratio of the additives to Example 1. Upon completion of the reaction, the crude product was treated with 7N ammonia/methanol solution, and the yield of methyl 3-aminobutyrate was analyzed by gas chromatography (GLC) using a TC-5HT capillary column. Further, after conversion of the product to methyl (3R)-3-(4-nitrobenzoylamino)butyrate, the enantiomeric excess was determined by high performance liquid chromatography (HPLC) analysis using a CHIRALCEL OD-H column. The specific reaction results are detailed in Table 1.
